title: A systematic review of controlled clinical trials on the prevention of back pain in industry.
abstract: OBJECTIVE
  To assess the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry.
  
  
  METHODS
  A computerised search for controlled clinical trials was conducted. A criteria list was used to assess the methodological quality of the studies. The available evidence for the effectiveness of the interventions was graded with a rating system for the level of evidence. Effect sizes of individual studies were combined if the studies were sufficiently similar.
  
  
  RESULTS
  11 studies were identified for the review. The methodological quality of all studies was low, with a maximum score of three out of seven for internal validity. There was no evidence for the effectiveness of lumbar supports due to contradictory outcomes of the studies. Five of the six studies on education reported no effect. Thus there is limited evidence that education does not help to prevent back pain. All three studies on exercise reported a positive result, indicating limited evidence for the effectiveness of exercise. The combined effect size for exercise was 0.53, which is a medium sized effect.
  
  
  CONCLUSIONS
  Although widely used, there is little evaluative research on the preventive measures studied here. The review showed that there is limited evidence that exercise has some effect in the prevention of back pain and that education is not effective. No conclusive evidence was found for or against the effectiveness of lumbar supports. Research of higher methodological quality is needed before firm conclusions on the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry can be drawn.
authors.affiliation: Institute for Research in Extramural Medicine, Vrije Universiteit, Amsterdam, The Netherlands. MNM.van_Poppel.EMGO@med.vu.nl
authors.forename: M N
authors.initials: MN
authors.lastname: van Poppel
authors.forename: B W
authors.initials: BW
authors.lastname: Koes
authors.forename: T
authors.initials: T
authors.lastname: Smid
authors.forename: L M
authors.initials: LM
authors.lastname: Bouter
mesh_terms: D001416:Back Pain / Q000517:prevention & control*; D018849:Controlled Clinical Trials as Topic; D015444:Exercise; D006266:Health Education / Q000379:methods; D006801:Humans; D009784:Occupational Diseases / Q000517:prevention & control*; D009989:Orthotic Devices